Abstract
Velocity distribution over a 70°-sweep delta wing with and without periodic flow excitation is experimentally investigated in a water tunnel at the USAF Academy. Periodic blowing and suction with zero net mass flux is applied at the leading edge of the wing. The velocity across the leading edge vortex is measured at angles of attack from 30° to 45°. All tests are performed at a freestream velocity of 0.12 m/s, corresponding to a chord Reynolds number of 3.3*104. It is found that periodic flow excitation significantly delays vortex breakdown. The efficacy of the periodic flow excitation in delaying vortex breakdown increases as the angle of attack increases. The vortex breakdown location is delayed by 0.25 chordlength at an angle of attack of 30° and by as much as 0.5 chordlength at an angle of attack of 45°. It is also found that periodic flow excitation increases the core velocity after the onset of natural breakdown. This is consistent with the results that were obtained in previous wind tunnel experiments with a similar, scaled-up wing. The increased velocity indicates a decreased pressure, hence a lift increase can be anticipated at angles of attack where vortex breakdown occurs without flow excitation.
Original language | English (US) |
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DOIs | |
State | Published - 2000 |
Event | 38th Aerospace Sciences Meeting and Exhibit 2000 - Reno, NV, United States Duration: Jan 10 2000 → Jan 13 2000 |
Other
Other | 38th Aerospace Sciences Meeting and Exhibit 2000 |
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Country/Territory | United States |
City | Reno, NV |
Period | 1/10/00 → 1/13/00 |
ASJC Scopus subject areas
- Space and Planetary Science
- Aerospace Engineering